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Messages - dmutz

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2
Hello,

for human toxicity potential and ecotoxicity potential I want to use USEtox model.
In some projects I am currently using ecoinvent v3.1 database. But in other projects ecoinvent v2.2.

Now, I noticed strong deviations in CF by using both databases (separately), that the characterisation factors for same materials with (more or less) the same emission type, e.g. water/river or water/surface, respectively.

Is this described fact just an error within the database or does ecoinvent v2.2 really account USEtox indicators with other CF than in v3.1?

An example (for ecotoxicity CF for USEtox w/o LT):
  • 1,4-Butanediol:
    • no CF (v2.2) - emission into water, river
    • 7,31 CTUe (v3.1) - emission into water, surface water
  • Cadmium, ion:
    • no CF (v2.2) - emission into water, river
    • 9 712 CTUe (v3.1) - emission into water, surface water
  • Mercury:
    • 22 090 (v2.2) - emission into water, river
    • 22 090 CTUe (v3.1) - emission into water, surface water

In this example: Mercury does have the same CF, but Cadmium has not. Why?

3
General / Re: Different Impact Result for same process ?!
« on: December 11, 2013, 15:54 »
Additionally, I checked the inventory of the processes "electricity" in the model for the material-output CO2,fossil [air/non-urban air...] and the electricity as output in each of the electricity-processes from ecoinvent in the Umberto model. Following specific value came out as result for each process (T10 to T13):

0,497 kg CO2-eq/kWh.

Thus, within the model, the inventory data are equal. The problem should be somewhere in LCIA calculation or transferring into excel?

When calculating only LCIA of the process of "electricity for ozonation" (command: "calculate selection" in the Umberto tool-menu), the specific GWP is given with:

643,6 g CO2/kWh (and again different from 568,2 g CO2/kWh when calculating the whole model).

4
General / Re: Different Impact Result for same process ?!
« on: December 11, 2013, 15:16 »
thank you for your answer!

yes, I did check the electricity process from ecoinvent separately. it is the value of 643,6 g CO2/kWh in this case... thus, three processes in my model have the true value, at least.

just for the basic understanding: in the model basically the treatment of treated wastewater is displayed (first ozonation, then mixing with a stream and other surface waters, then phosphorus removal before it is led to a lake preventing eutrophication).

anyway, today I updated the volumetric load going through the process "ozonation". there is now a reduction of 6,5% of water going through "ozonation", so the electricity consumption is reduced by 6,5% accordingly. BUT now the CO2-emissions increased by 10% in this process. there were no other changes made in this process.
now, the specific value for "electricity for ozonation" is 568,2 g CO2/kWh... yesterday it was 504,0 g CO2/kWh...

therefore, changing materials properties from "good" into "bad" doesn't seem to be the solution for the origin of this problem... from my understanding, in the excel-file the absolute amount of kg CO2 emissions per process should be displayed as it was in former Umberto 5.6, or not?

kind regards!

5
General / Different Impact Result for same process ?!
« on: December 10, 2013, 15:27 »
Hello,

in my current LCA study, I am modelling wastewater treatment technologies. thus, the model has its characteristics more like a MFA-model than a typical LCA-model considering the distinct life cycle stages such as production-phase / use-phase etc.
in the attachment I put one example.

now the problem:
by dividing the impact result from the excel-file (export LCIA raw data) by the specific material flow, there are different results coming up.

as an example, I put here the electricity:

dividing the GWP-impact from electricity used [kg CO2-eq] by the amount of electricity used [kWh] there are some deviations, which should not be the case...

in following processes electricity has an impact of 643,6 g CO2-eq/kWh:
  • T10 (electricity used in T02: Vermischung Volumenströme)
  • T11 (electricity used in T05: P-Entfernung)
  • T90 (electricity produced in T90)

in the next processes, there are others quotients calculated from the results of the excel-file:
  • T12 (electricity used for Subnet: Schlammbehandlung): 530,2 g CO2/kWh
  • T13 (electricity used for Ozonation): 504,0 g CO2/kWh

First, there were different quotients for all processes. So, I thought by setting the allocation manually in each single process, I could fix the problem. But still, the specific impact-factor of electricity (probably 643,6 gCO2-eq/kWh) is not unique in all processes.
in the other attachments, there is an example how a process and the allocation is done (here: ozonation).

Can anyone help?

6
Hello,

still I have no answer to the question above. I am still waiting...

But another question emerged to the issue of LCIA in Umberto:

Is there a possibility to edit the existing LCIA valuation systems or to create own valutation systems similar to the valuation editor in Umberto 5.6?

7
Thank you for your reply!
I started to ask ecoinvent support for an answer, as soon as I get an information about the topic, I will let you know.

8
Hello Mr. Beilschmidt,

thank you a lot for your quick reply. Now, I think I get the problem!
I checked the figures, you've provided for lignite. It is not a failure in the installation of the database in my case. It is a problem of the chosen database (and possibly an error within the ecoinvent v3.0 database?):

In the attached screenshots (from ecoinvent website) you can see a difference in versions 2.2 and 3.0:

Use of "electricity, lignite, at power plant [DE]" (ecoinvent v2.2) leads to:

ReCiPe Midpoint (H)/freshwater ecotoxicity
0.038264 kg 1,4-DCB-Eq per kWh
and
ReCiPe Midpoint (H) w/o LT/freshwater ecotoxicity w/o LT
0.00018148 kg 1,4-DCB-Eq per kWh

Use of "electricity production, lignite, DE" (ecoinvent v3) leads to:
ReCiPe Midpoint (H)/freshwater ecotoxicity
0.040201 kg 1,4-DCB-Eq per kWh
and
ReCiPe Midpoint (H) w/o LT/freshwater ecotoxicity w/o LT
0.040201 kg 1,4-DCB-Eq per kWh

Since I used the ReCiPe Midpoint method without longterm emissions it has changed significantly in my case. Or there is a problem with the "ReCiPe Midpoint (H) w/o LT" method...?! Comparing all indicators, there is no change between with LT and w/o LT, which leads to the question, why there is a distinction between longterm and no-longterm emission?

9
Hello,

I noticed following problem while modelling an own energy mix with ecoinvent v3.0 data: there are some large deviations in LCIA results comparing to the same energy mix by using econinvent v2.2 data in LCA NXT. I used ReCiPe Hierarchist w/o LT for the comparison.

Following deviations in results seem pretty unrealistic only due to updates in the database (just an exerpt):
Windpower (onshore)
  • freshwater ecotoxicity
         
    • v2.2 "electricity, at wind power plant 800kW [RER]": 1,1*10^(-4) kg 1,4-DCB/MWh
    • v3.0 "electricity production, wind, 1-3MW turbine, onshore [DE]": 0,6 kg/MWh
  • climate change
         
    • v2.2 "electricity, at wind power plant 800kW [RER]": 0,17 kg CO2-eq/MWh
    • v3.0 "electricity production, wind, 1-3MW turbine, onshore [DE]": 22 kg CO2-eq/MWh
Lignite
  • freshwater ecotoxicity
         
    • v2.2 "electricity, lignite, at power plant [DE]": 0,17 kg-DCB/MWh
    • v3.0 "electricity production, lignite [DE]": 40,9 kg DCB/MWh
  • climate change (comparable results between new and old database!)
         
    • v2.2 "electricity, lignite, at power plant [DE]": 1,24 kg CO2/kWh
    • v3.0 "electricity production, lignite [DE]": 1,25 kg CO2/kWh

By analyzing the results, I noticed that ReCiPe (H) w/o LT, take also category factors into account for long term emissions. Is that an error in the LCIA programming within the software? By comapring LCIA data, ecoinvent v3.0 includes long-term emissions (and they have large impacts, which lead to the higher Impacts in most categories) and ecoinvent v2.2 does not include those long-term emissions. But both energy-mixes were calculated at the same time (in Umberto NXT LCA with ReCiPe (H) w/o LT)

If it is an error in the LCIA programming, it seems old ecoinvent v2.2 has no long-term emissions in their dataset (if they had, there would/should be still comparable results)?

Thank you in advance for answering!
Regards, D. Mutz

10
General / input monitor in Umberto NXT available?
« on: May 22, 2013, 11:09 »
Hello,

in Umberto 5.6 there was an "input monitor" available, so you could set the input flow for different scenarios simulaneously. Is there a similar function given in Umberto NXT LCA or should the input flow set manually for each scenario now?

Kind regards

11
General / iterative calculation with dynamic modeling?
« on: May 22, 2013, 10:59 »
Hello,

in Umberto 5.6 I used the function of "dynamic modeling" for an iterative material flow calculation within the model. If haven't found a similar function in Umberto NXT yet. Is it still possible to do some iterative calculations?

Regards

12
Thank you for your quick reply!

The reason for the question was to merge the inventory data by exporting from a subnet and importing into a single transition. In that specific case, I want to create different Electricity Mix for specific cases. Thus, by copying the whole subnet, I think it will paste and calculate the whole module (and furthermore about 13 times the same material for each transition such as wind power, photovoltaic mix, hard coal etc.).

However, the copy&paste function through Module Gallery is a good way! Thank you so far.

As you said "not available yet", is it intended to implement such an import function with excel files?

13
General / Export of a model into a transition (or process)
« on: April 30, 2013, 17:15 »
Hello,

in Umberto 5.6 it was possible to export a whole subnet or a whole calculated net into a spreadsheet, which you could import into a single transition and use this transition as a new one through export this transition.

I couldn't find a similar function in Umberto NXT LCA yet. Is there any possibility to create such a transition from exporting a spread sheet of a calculated net?

Kind regards!

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